The new and improved catalysts and methods of this invention involve dispersing on a finely divided and difficult to reduce inorganic oxide selected from silica, alumina, thoria, zirconia, titania, magnesia and mixtures or composites thereof an organic chromium complex such as a chelate derived from orthohydroxyphenyl or 2'-hydroxyphenyl carbonyl compounds, including ketone, aldehyde and amide types, and their derivatives, and activating the resulting mixture by heating to and at an elevated temperature in a non-oxidizing atmosphere with a specific temperature range being within about 600.degree.-2000.degree. F.